Patent GB-252744-A (GB)
Title: Nut tapping machine
IPC: B23G1/18
Filed: 1926-05-31
Abstract: 252,744. Budd Wheel Co., (Assignees of Vis, G. A.). June 1, 1925, [Convention date]. Tapping nuts; blanks, transferring. -In a nut-tapping machine the nuts are fed singly and yieldingly to the tap and are released from tapping position only when a sufficient length of thread has been cut. The tapspindle 15 is rotatably mounted in two fixed sleeves 18, 22, Fig. 3, and has splined thereon a sleeve 21 keyed to the male member 26 of a frictionclutch which may engage either of two oppositely rotating belt-pulleys 29, 30 driven by a motor (not shown). Slight endwise movement of the spindle to engage either drive is produced by the pressure of the work on the tap 17. The nuts 61 to be tapped are supplied to a vertical shoot 55 pivoted at 58 on a cross-member 54 supported by columns 51 on a slide 34 which is pressed towards the tap by an adjustable spring 102 and is intermittently retracted by a cam 36 rotated through worm gearing 40 from a shaft 41 splined to a belt-pulley 42. The cam is mounted on a carriage 33 which may be adjusted to and from the tap by a screw 46. The lowest nut is supported by a trigger 76, Figs. 3 and 4, which is retained in the supporting position shown by a detent 78, and in operation the slide 39 is moved forwards yieldingly by the spring 102 until the second nut from the bottom of the shoot meets the tap and engages the clutch 26, 30, to rotate the tap in the cutting direction. The tap then feeds the slide 34 forwards and during this movement a projection 82 on the detent 78 encounters an adjustable fixed stop 83 to withdraw it and allow a spring 77 to rotate the trigger 76 and release the bottom finished nut which falls out by gravity into a shoot 110. After a predetermined interval the cam 36 causes the slide 34 to recede and exerts a tractive effort on the spindle 15, which, through a collar 106', a spring 107 and the sleeve 21, yieldingly disengages the driving clutch and engages the reverse clutch. The stop 83 is adjusted so that if the nut has been tapped to the required depth the slide 34 has moved far enough for the parts 82, 83 to engage, whereas if the tap has not penetrated sufficiently far into the nut the parts 82, 83 will not meet and the trigger will continue to support the bottom nut and will thus cause the nut above to be operated upon repeatedly until it has been tapped to the required depth. On the return stroke of the slide 34. if the trigger 76 has been tripped, a projection 86 on the trigger engages a spring abutment 87 on the stationary carriage 33 so as to rotate the trigger about its pivot 72 and the detent then locks it in position for supporting the nut which drops on to it after having been screwed off the tap. A guard a prevents the driving belts from being splashed by lubricant which is supplied to the tap by a conductor or container carried by a support b. Work-holders.-During tapping the nut to be operated upon is supported in correct alignment with the axis of the tip by three fingers 91, Fig. 7, projecting through an orifice in the shoot 55 and carried by a head 92 which is yieldingly pressed forwards by springs surrounding two horizontal rods for supporting the head, the rods sliding in bushes mounted on either side of the slide 34. Two guide rods are also provided on the head and slide through side bushes on the spindle bearing 14. The fingers engage the conical or hemi-spherical ends 62 of the nuts and cause machined faces 66 thereon to be pressed into intimate contact with machined surfaces 65 on the side rails 60 of the shoot so as to ensure that the tapped holes shall be perpendicular to the faces 66. On the return stroke of the slide 34 two adjustable stops thereon engage the ends of the rods supporting the head and cause the head to recede against its spring pressure to allow the tapped nut to drop, if the trigger 76 has been tripped. The shoot has slight freedom of movement about the pivot 58 to allow the nuts to move lateral.y into alignment with the tap.